1. Field of the Invention
The present general inventive concept relates to an image forming apparatus, and more particularly, to an ink ejection device usable with a page printing type image forming apparatus, an image forming apparatus using the same, and a method thereof.
2. Description of the Related Art
An ink-jet type image forming apparatus ejects ink drops on a printing medium (e.g., paper) to form an image on the printing medium. The ink-jet type image forming apparatus may be classified as a line printing type and a page printing type (i.e., a wide array type inkjet head). The line printing type image forming apparatus includes a print head that ejects ink drops and reciprocates back and forth along a widthwise direction of the printing medium to form the image. The page printing type image forming apparatus also includes a print head, and a plurality of nozzles is arranged in the print head as long as a width of the printing medium. The page printing type image forming apparatus forms images in a line of the printing medium at once while the printing medium is being conveyed. In other words, the page printing type image forming apparatus can form an entire line of the image at one time.
A printing resolution of the line printing type image forming apparatus can be controlled by controlling a conveying speed of the printing medium. That is, it is possible that the line printing type image forming apparatus forms images with a higher printing resolution by reducing the conveying speed of the printing medium. If the conveying speed of the printing medium is reduced, images are formed even on a printing area on the printing medium between nozzles. As a result, the images can be formed with the higher printing resolution. However, it is difficult to control a printing resolution of the page printing type image forming apparatus by controlling a conveying speed of the printing medium, since the print head is typically fixed in the page printing type image forming apparatus and is not movable therein. Therefore, it is difficult to form images on the printing area on the printing medium between the nozzles using the page printing type image forming apparatus.
As described above, it is difficult to form images with higher printing resolution using the page printing type image forming apparatus, since the printing resolution is limited by a nozzle printing resolution that is defined by nozzles (i.e., a nozzle arrangement) of the print head. Therefore, research has been performed in an effort to improve the nozzle printing resolution by arranging a number of nozzles in a unit area of a head chip. However, arranging and/or increasing the number of nozzles in the unit area of the head chip typically decreases a yield of the head chip.
Furthermore, a heater for ejecting the ink may be easily deteriorated or an ink-ejection path may be blocked because the head chip may be inferior or may be used for a long-time use. As a result, some of nozzles may malfunction. The malfunctioning nozzles cannot eject ink drops. Thus, the nozzles that malfunction form a white line on the image printed on the printing medium, since no image is formed by the malfunctioning nozzles.